The LPS is provided by LGC Promochem AB, Albanoliden 5, 4tr, 506 30 Borås, Sweden. The USP (United States Pharmacopeial Convention) Endotoxin (Cat. No. 1235503) does come as a lyophilized (freeze-dried) powder and each vial contains 10,000 USP Endotoxin Units. Each vial contains very approximately 1 microgram of Endotoxin and is mixed with 5 milliliter (mL) of sterile water.